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Open channel Boundary Conditions

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Old   November 23, 2016, 13:12
Default Open channel Boundary Conditions
  #1
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Milad
Join Date: May 2016
Location: Tehran
Posts: 3
Rep Power: 7
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Hi dear Foamers
I am trying to run an 2 phase flow in Version 2.4 since methods are changed from 2.3 for interFoam.
and I have problems with that.
1. my first problem is should I Split both outlet and inlet in to 2 face,(water and air separately)?
I caught the free surface (alpha.water) correctly but for Velocity I just Need the water velocity but air have non zero velocity too.
there is my U and alpha.water
any ideas?
thanks
the first 2 codes have 2 inlets
Code:
-*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2.4.0                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       volScalarField;
    object      alpha.water;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
dimensions      [0 0 0 0 0 0 0];

internalField   uniform 0;

boundaryField
{
    inlet-air
    {
        type            fixedValue;
        value           uniform 0;
    }

    inlet-water
    {
        type            fixedValue;
        value           uniform 1;

    }
    outlet
        {
    type         zeroGradient;

}

    atmosphere
        {
             type         inletOutlet;
            inletValue      uniform 0;
                value           uniform 0;
        }

        walls
            {
           type            zeroGradient;

            }
        rib
            {
           type            zeroGradient;

            }
        front
            {
                type empty;
        };

        back
            {
                type empty;
        };
};
Code:
/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2.4.0                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       volVectorField;
    object      U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //dimensions      [0 1 -1 0 0 0 0];

internalField   uniform (0.1 0 0);

boundaryField
{
inlet-air
    {
        type            fixedValue;
        value           uniform (0 0 0);
    }
    
    inlet-water
    {

       type      fixedValue;
        value    uniform (0.1 0 0);
 
    }

    outlet
      {
        //type       zeroGradient;
        type            pressureInletOutletVelocity;
        value           uniform (0 0 0);
      }

    atmosphere
    {
        type            pressureInletOutletVelocity;
        value           uniform (0 0 0);
    }
    
   walls  
    {
       type            fixedValue;
     value           uniform (0 0 0);


    }

 rib
    {
        type            fixedValue;
        value           uniform (0 0 0);
     
    } 

        front
            {
                type empty;
        };

        back
            {
                type empty;
        };
}
Code:
/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2.4.0                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       volScalarField;
    object      alpha.water;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //


dimensions      [0 0 0 0 0 0 0];

internalField   uniform 0;

boundaryField
{
    inlet//has changed from inlet-water & inlet-air to inlet
    {
      type            variableHeightFlowRate;
        lowerBound      0.0;
        upperBound      0.5;
        value           uniform 1;
 
    }

    outlet
        {
    //type        inletOutlet;
    //inletValue    uniform 0;
    type         zeroGradient;

      
        }


    atmosphere
        {
        type         inletOutlet;
            inletValue      uniform 0;//Like Spillway tut
                value           uniform 0;
        }

        walls
            {
           type            zeroGradient;

            }
        rib
            {
           type            zeroGradient;

            }
        front
            {
                type empty;
        };

        back
            {
                type empty;
        };
};

Code:
/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2.4.0                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       volVectorField;
    object      U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 1 -1 0 0 0 0];

internalField   uniform (0.1 0 0);



boundaryField
{
        inlet
        {
               type            fixedValue;
            value           uniform (0.1 0 0);

        }


        outlet
        {
        type         zeroGradient;
      
         }


     atmosphere
        {
                type            pressureInletOutletVelocity;
               phi             phi;
                value           uniform (0 0 0);
        }

    walls
           {
               type            fixedValue;
            value           uniform (0 0 0);
         }


       rib
        {
        type            fixedValue;
         value           uniform (0 0 0);
        }

        front
            {
                type empty;
        };

        back
            {
                type empty;
        };

};


// ************************************************************************* //
at the end I use 0.9 for upper bound but I get nothing!
type variableHeightFlowRate;
lowerBound 0.0;
upperBound 0.9;
value uniform 1;
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Old   December 2, 2016, 02:25
Default
  #2
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Nima Samkhaniani
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whats wrong?
the air has a motion becuase there is shear stress between phases.
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boundary conditions, interfoam, open channel flow

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